During sex, you're probably not thinking things like, "Wow, my dilated blood vessels have allowed more blood to rush to my vagina, resulting in extra-pleasurable sensations!" But the truth is that when you're aroused or having sex, your body and brain are lighting up like a pinball machine and doing various things to make the experience as mind-blowing as possible.

The process your body undergoes when you get turned on and have sex is called the sexual response cycle. "It’s this symphony of activity," Jamil Abdur-Rahman, M.D., board-certified ob/gyn and chairman of obstetrics and gynecology at Vista East Medical Center in Waukegan, Illinois, tells SELF.

Scientists breaks the sexy cycle into five phases that take place from the moment you get turned on to the exhausted, blissed-out comedown. Here’s what goes down when you get down:

Phase 1: Desire (Or the part where you start to really want it)

Cleveland Clinic doesn't list desire, or the feeling of wanting to have sex, as an official part of the sexual response cycle. But Planned Parenthood does, and for good reason: It's hella important, especially for women. "In the beginning of a relationship, many women do experience spontaneous desire the way it's portrayed in the media, as couples ripping each other’s clothes off after a single sexy glance," sex therapist Ian Kerner, Ph.D., author of She Comes First, tells SELF. "But research has borne out that for many women, desire is responsive, meaning that it responds to something that comes before it [like physical arousal]."

So, for some women (especially when in a new relationship or when hooking up with someone new and exciting), desire might come first. But for others, it may not kick in until after the fooling around has commenced, and that's totally normal, says Kerner.

Phase 2: Excitement (aka IT’S ON!)

Your body is either responding to desire or to some sort of stimulation from your partner. Here's what happens.

2. Depending on your skin color, you may notice what's called a "sex flush," or reddening skin, creeping up around your chest and neck.

3. "Your body releases more nitric oxide, which causes your muscles to relax and also causes the blood supply to the vagina and cervix in particular to increase quite a bit," says Abdur-Rahman.

4. That extra blood flow also triggers vaginal lubrication.

5. Your clitoris, the star of the orgasm show, is officially reporting for duty. Made of the same kind of erectile tissue as a penis, your clitoris has the ability to get "erect" once it starts filling with blood.

6. There's also this thing called tenting, which is when the part of your vagina close to the cervix will dilate while the lower part constricts a bit. "[The dilation] may make it easier for the vagina to receive a penis, and it creates a sort of suctioning action that helps direct sperm to the cervix," says Abdur-Rahman.

7. Meanwhile, thanks to excess blood flow, your nipples may become erect and feel more sensitive. In fact, all areas of your breasts might feel more sensitive the more turned on you get, so encourage your partner to explore. "Some things that may feel uncomfortable at beginning of sex, like, oh, that itches, tickles, or hurts may actually feel really good towards when a woman is highly aroused," says Kerner.

8. In the long buildup to eventual orgasm, your muscles start tensing up.

Phase 3: Plateau (Where it’s still on—seriously, wonderfully on)

This phase is definitely not as boring as the name makes it sound. While you're having sex or messing around, you feel "prolonged, intense sexual arousal," says Planned Parenthood. Everything that was already happening before continues, plus a few fun additions.

9. "There's increased activity in pleasure centers in the brain like the amygdala and the hippocampus," says Abdur-Rahman. Also, at this point everyday stressors are hopefully falling away. "The more aroused women get, the more parts of the brain associated with anxiety shut down," which is a key part of orgasm for women, says Kerner.

10. Your levels of dopamine and epinephrine are on the rise. Dopamine is a feel-good neurotransmitter, and epinephrine is more commonly known as adrenaline. "It helps to ensure blood flow is being directed to the areas that are most important for sexual activity, like skeletal muscles, which help with voluntary movements like thrusting," says Abdur-Rahman. Adrenaline also helps you have enough energy for the action, he explains.

11. Your vagina is undergoing some truly magical changes, like your vaginal walls turning a deep purple color. That's probably hard to see—and stopping just to check it out might not be on your agenda—but your labia minora also darken, which you would theoretically be able to notice.

13. The Bartholin's glands, which may be a major player in female ejaculation, release more vaginal lubrication.

14. The clitoris is becoming even more sensitive than usual. Knowing what's good for it, it retracts under the clitoral hood to avoid becoming over-stimulated.

Phase 4: Orgasm (Where you orgasm. Or don’t. It’s all good.)

Aaand we're here. During sexual climax, everything basically goes haywire in the best way possible (of course, sex is still great even if you don’t orgasm).

15. Your heart rate, breathing, and blood pressure are at their peak.

16. Although your levels of various neurotransmitters increase as you get aroused, orgasm is officially go-time. "There's a big increase in the production of oxytocin," or the feel-good hormone, says Abdur-Rahman. In addition to boosting your pleasure, oxytocin can cause the uterus to contract, potentially to help semen get drawn up through the cervix.

17. Your muscles are convulsing, hard. Specifically, the vagina, anus, muscles of the pelvic floor, and sometimes even the uterus contract five to 12 times with just 0.8 seconds between each contraction, according Planned Parenthood.

18. You might experience female ejaculation, although when it occurs, it doesn't always happen in conjunction with orgasm.

Phase 5: Resolution (The part where you get to snuggle, or fall asleep, or go again.)

High five. Here's what you can expect once it's all over.

19. Everything from your heart rate to your breasts to your labia basically goes back to normal, except your cervix, go-getter that it is. "[The] opening of the cervix remains open. This helps semen travel up into the uterus. After 20 to 30 minutes, the opening closes," says Planned Parenthood. You may also feel awash in the post-orgasm glow thanks to that rush of oxytocin.

While this resolution usually leads to a refractory period for men, or a time when they physically can't have sex, that's not so for women. "Some women are capable of a rapid return to the orgasm phase with further sexual stimulation and may experience multiple orgasms," says Cleveland Clinic. Time for round two?